Generalised proxies (#6156)

* Initial work

* It should work

* Fix node

* Fix tests

* Initial test

* Tests

* Expunge proxy functionality from democracy and elections

* Allow different proxy types

* Repotted

* Build

* Build

* Making a start on weights

* Undo breaking change

* Line widths.

* Fix

* fix tests

* finish benchmarks?

* Storage name!

* Utility -> Proxy

* proxy weight

* add proxy weight

* remove weights

* Update transfer constraint

* Again, fix constraints

* Fix negation

* Update frame/proxy/Cargo.toml

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Remove unneeded event.

* Grumbles

* Apply suggestions from code review

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

substrate/Cargo.lock

@@ -3609,6 +3609,7 @@ dependencies = [
  "pallet-membership",
  "pallet-offences",
  "pallet-offences-benchmarking",
+ "pallet-proxy",
  "pallet-randomness-collective-flip",
  "pallet-recovery",
  "pallet-scheduler",
@@ -4399,6 +4400,22 @@ dependencies = [
  "sp-std",
 ]
 
+[[package]]
+name = "pallet-proxy"
+version = "2.0.0-rc2"
+dependencies = [
+ "frame-benchmarking",
+ "frame-support",
+ "frame-system",
+ "pallet-balances",
+ "parity-scale-codec",
+ "serde",
+ "sp-core",
+ "sp-io",
+ "sp-runtime",
+ "sp-std",
+]
+
 [[package]]
 name = "pallet-randomness-collective-flip"
 version = "2.0.0-rc2"